Transmission with variable volume vane pump



Aug. 13, 1968 Y. E. MOOCHHALA ETAL 3,396,666

TRANSMISSION WITH VARIABLE VOLUME VANE PUMP ug 13, 1958 Y. E. MoocHHALAETAL TRANSMISSION WITH VARIABLE VOLUME VANE PUMP 5 sheets-sheet z FiledDec. 13, 1965 Aug. 13, 1968 Y. E. MoocHHALA EVAL 3,395,566

TRANSMISSION WITH VARIABLE VOLUME VANE PUMP Filed Dec. 13, 1965 5Sheets-Sheet 3 @Lw ,JFIL @5M/nw TRANSMISSION WITH VARIABLE VOLUME VANEPUMP Filed DSC. 13, 1955 Aug- 13, 1968 Y. E. MoocHHALA ET AL 5Sheets-Sheet 4 Aug. 13, 1968 Y. E. MQOCHHALA ET AL 3,396,666

TRANSMISSION WITH VARIABLE VOLME VANE PUMP 5 Sheets-SheetI 5 Filed DeC.15, 1965 United States Patent O 3,396,666 TRANSMISSIGN WITH VARIABLEVOLUME VANE PUMP Yumus E. Moochhala, Bombay, India, and Ronald H. Haas,Mount Prospect, Ill., assignors to Borg-Warner Corporation, Chicago,Ill., a corporation of Illinois Filed Dec. 13, 1965, Ser. No. 538,435 6Claims. (Cl. ID3-120) ABSTRACT F THE DISCLGSURE A variable volume fluidpump having a rotor with vanes mounted in slots therein and a cam ringsurrounding the rotor. A port plate adjacent the rotor. A pair of fluidcavities in the port plate. The port plate having alternate inlet oroutlet cavities and arcuate ports providing communication between thecavities and a plurality of the spaces formed `between the vanes, rotorand cam ring. Second arcuate ports in the port plate communicating fluidpressure to the inner radial end of the vanes to urge the vanes intoengagement with the cam ring.

This invention relates to a hydraulic transmission. More particularly,this invention relates to a hydraulic transmission for an automaticclothes washer including an improved pump structure.

It is an object of this invention to provide an improved transmissionfor the clothes basket and agitator drive of an automatic clothes washercomprising a variable volume iluid pump operable in two directions ofrotation. The improved hydraulic transmission includes an i-mprovedvariable volume fluid pump operable to deliver duid pressure to a fluidmotor to spin the clothes basket of the washer when the pump is operatedin one direction and operative to `deliver fluid pressure to a uid motorto operate the agitator of the washer when the pump is operated in areverse direction of rotation.

It is further an object of this invention to provide an improvedvariable volume luid pump of the vane type in which fluid pressure isutilized to balance the vanes and hold the vanes in an operativeposition without the necessity of incorporating springs as known in theprior art.

It is a further object to provide an improved variable volume fluid pumpwherein large cavities lfor the intake and exhaust ports are providedinsuring adequate iluid ilow through the pump.

The invention consists of the novel constructions, arrangements anddevices to be hereinafter described and claimed for carrying out theabove stated objects and such other objects as will appear from thefollowing description of the preferred embodiment of the inventionillustrated with reference to the accompanying drawings wherein:

FIGURE 1 is a schematic view of a hydraulic transmission for a clotheswasher during the agitate cycle em- Ibodying the principles of theinvention;

FIGURE 2 is a schematic view showing the hydraulic transmission duringthe spin cycle operation;

FIGURE 3 is a schematic view showing the hydraulic transmission duringthe spin brake cycle;

FIGURE 4 is a cross-section view of the control system and Variablevolume pump for the transmission;

FIGURE 5 is a sectional view taken along the line '5--5 of FIGURE 4showing the cam operation for the control mechanism;

FIGURE 6 is a sectional view taken along the line 6-6 of FIGURE l;

FIGURE 7 is a top view partially in section of the variable volume pump;

ICC

FIGURE 8 is a cross-sectional view taken along the line 8--8 of FIGURE7;

FIGURE 9 is a cross-sectional view taken along the line 9 9 of FIGURE 7and FIGURE 10 illustrates a modified form of the agitate motor shown inFIGURE 1.

Copending application Ser. No. 538,434 entitled Hydraulic Transmissionand of common assignee, includes a complete description and claims tothe hydraulic transmission in general in which the mechanism of thepresent description would be utilized. The mechanism described andclaimed herein relates to an improved variable volume pump structure foruse with the hydraulic transmission described in the above mentionedcopending application.

Referring to FIGURE l, a hydraulic transmission 10 is illustrated fordriving the clothes basket 11 or the agitator 12 of an automatic clotheswasher. A motor 13 is provided having a water pump 14 driven thereby forrecirculating Water in the clothes basket of the automatic washer and asource of power 15 is illustrated tor operating the motor 13. A cycleselector switch 16 is schematically illustrated in a simplitied formalthough in a washer installation this function would be performed by atimer switch mechanism of known construction.

The important elements of the hydraulic transmission are as follows: avariable volume reversible fluid pump 20; a control valve mechanism 21for the pump 20; an agitator drive motor 22; a clutch mechanism 23 forengaging the agitator drive; a spin motor 24, a lock mechanism 25 forthe clothes basket 11, and a spin brake valve 26.

A lid 30 is illustrated for the clothes basket of the washer including asafety switch mechanism 31 which is operable to interrupt the powersupply to the motor 13 when the lid 36 is raised.

A uid sump 32 is provided which is schematically illustrated forconvenience at various places in the schematic illustration of theinvention although in the actual construction one fluid sump 32 isprovided into which all the exhaust connections for various elements ofthe transmission exhaust fluid pressure. Electric wires 33 and 34interconnect the source of power 15 with motor 13, the line 34 beingaground line. Wire 35 connects the source of power 15 to switchmechanism 16. Switch mechanism 16 is connected to the motor by a wire36. A wire 37 connects safety switch 31 to the switch mechanism 16. Awire 38 connects safety switch 31 to the motor 13.

A fluid conduit 40 is provided which is connected to the variable volumepump 20, the control valve mechanism 21, spin motor 24 and the spinbrake valve 26. A fluid conduit 41 is provided which is connected to thevariable volume pump 20, to control valve mechanism 21, agitator drivemotor 22, lock mechanism 25 and the clutch mechanism 23. A iluid conduit42 connects spin motor 24 with spin brake valve 26.

Conduit 41 is connected to the fluid sump 32 through a check valve 45which allows fluid flow only fin the direcltion from the sump intoconduit 41. Conduit 40 is connected to the fluid sump 32 through a checkvalve 46 which allows fluid ilow only in a direction rfrom the sump 32into conduit 40. The variable volume pump 20 is also connected to thefluid sump 32 by a conduit 47. The lock mechanism 25 is connected to thefluid sump -32 by conduit 48 and the spin brake valve 26 is connected tothe fluid sump 32 by conduits 49 and 50.

Referring to FIGURES 4, 7, 8 and 9 the variable volume purrip 20 is moreparticularly illustrated. The showing in FIGURE 1 schematicallyrepresents the fluid passages within the pump while in FIGURES 7, S and9 the actual structure of the pump is illustrated. 'Ilhe pump 20 has acam ring 55 which is slidably disposed in a pump body es 56. A spring 57urges the 4slidable cam ring 55 to the left as illustrated in FIGURE land the control mechanism 21 will urge the slidable cam ring 55 to theright, the spring unging the oam ring to a position of minimum pumpdisplacement.

The pump further includes a rotor 58 having a plurality of vanes 59slidably disposed in slots 59a in the trotor. The outer ends of vanes 59engage an internal surfalce 60 of the cam ring 55. The rotor isconnected to be driven by 'a shaft 61 which is driven by the electricmotor 13 of the transmission.

Disposed immediately above the motor and cam ring of the pump is a portplate 62 which has large rectangularshaped cavities 63 and 64 therein.Above the port plate 62, as illustrated in FIGURE 9, a body member 67 isdisposed which has fluid passages formed therein. A passage 68 isconnected to cavity 63. A passage 69 is connected to cavity 64. Passage69 is connected as illustrated in FIG- URE 4 to the fluid conduit 41 andthe passage 68 is connected to the fluid conduit 40.

In the area of the port plate 62 between cavities 63 and 64 an elongatedrecess 71 is formed which extends parallel to cavities 63 and 64. Arecess 72 intersecting the recess 71 is formed transverse or at rightangles to the .recess 71. The recess 72 is connected to the cavity 63 bya passage 73 and to the cavity 64 by a passage 74. A ball 75 is disposedwithin the recess 72 and is engageable to block either of the passages73 or 74. Vertical Ipassages 76 and 77 are connected to the recess 71.Passages 76 and 77 terminate in elongated arcuate .ports 78 and 79.

Formed in the bottom of cavity 63 is a large arcuate port 82 and a smallarcuate port S3. Formed in the bottom of the cavity 64 is :a largearcuate port 84 and a small arcuate port 85.

The large arcuate ports, 82 and S4, are the ports through which uid isdrawn into and forced out of the pump 20. One being a pressure port oroutput port and the other being an intake port depending upon thedirection of rotation of the -pump rotor. Arcuate ports 78, 79, 83 and85 communicate pressure to the back of the vanes y59 to hold them-radially outwardly in contact with the cam surface 60 when the pump isoperating to ensure that the force on the vanes is balanced and thatthey will remain in engagement with the cam surface. The recesses 72 and71 in cooperation with ball 75 are constructed so that only the pressureside of the pump or the side from wlhich fluid pressure is beinglsupplied to the system and the slots under ports 78 and 79 will have ahigh pressure uid imposed on the vanes for balancing, while on the lowpressure side of the pump only inlet pressure will be imposed on thevanes for balancing.

The variable volume pump 20 described above is operative to pump fluidin either direction of rotation and thereby supply fluid pressure eitherto conduit 40 or conduit 41. Movement of the lslidable cam ring 55 tothe right against the force of spring 57 will increase the displacementof the variable volume lpump by increasing the eccentricity of the rotorwith respect to the cam ring.

Referring to FIGURES l, 7, 8- and 9, as the pump is rotated in thecounterclockwise direction by the electric motor as viewed in FIGURE 7,the lcavity 64 will become the pressure outlet recess for the pumpsupplying uid pressure to passage 69 and thereby to luid conduit 41.When the pump rotates counterclockwise as viewed in FIGURE 7, in thearea of the pump just under the port 84 the volume of the spaces betweenthe vanes 59 is decreasing as the rotor turns thereby squeezing uidthrough port 84 into cavity 64 and out passage 69. In the area of thepump under cavity 63 the volume of the space between the vanes 59 isincreasing as the rotor rotates thereby creating a vacuum and drawingfluid into the pump through passage 68, conduit `40, check valve 46frorn the sump 32. As stated tabove, operation of the control mech*anism 21 will change the displacement of the pump moving slidable camring against the force of spring 57.

An improved pressure balancing system is utilized with the present pumpto hold the vanes against the cam ring surface during rotation of therotor. The ports 78, 79, 83 and 85 yare the pressure balancing ports.Assuming tlhe pump is rotating in the counterclockwise direction fluidfrom cavity 64 will flow through passage 74 into the trecess 72 andrecess 71. The ball 75 is thereby forced to the left as viewed in FIGURE9 blocking passage 73 and trapping high pressure iiuid in recess 71.

The high pressure fluid in recess 71 will then flow through verticalpassages 76 and 77 into arcuate ports 78 and 79 whereby it will beimpossed on the inner end of the vanes 59 in the area of the `arcuateports 78 and 79. High pressure in cavity 64 will also tiow through port85 to the inner side of the vanes 59 in the area of the cavity 64. Thusthe vanes on the high `pressure side of the pump having thigh pressureimposed on the inner end thereof to hold them out against the camsurface 60 and to pres- -sure balance the vanes 59 due to the equalizingpressure imposed on the inner end thereof.

It will be apparent that when the pump is operated in the clockwisedirection the ball will block passage 74 and the area of the pump undercavity 63 will be pressurized and fluid pressure will again be conductedfrom recess 71 and the passages 76 and 77 to pressure balance vanes asthey move between the area of the cavities 63 and 64. Therefore in theclockwise direction of the pump due to the action of the ball 75 and thefluid passagers connected thereto the pressure side of the pump willagain thave balanced vanes and the vanes will be orced into engagementwith the cam surface 60. In this manner springs or other devices to holdthe vanes in engagement with the cam surface 60 are unnecessary.

Referring to FIGURES l and 4, the control mechanism 21 for pump 20includes a pair of control elements 90 and 91. The control element isadjustable by a cam 92 and the control element 91 is adjustable by -acam 93. An extension 94 of pump body 56 is provided which includes apair of stepped bores 95 to contain the control elements 90 and 91. Thebores 95 have a irst section 96, 'a second section 97 of a smallerdiameter, and a third section 98 of smaller diameter than section 97.

The control elements 91 and 90 each include a pin 101 `raving a guide102 mounted thereon which is prevented from sliding olf the pin by asnap ring 103. The guides 102 are engaged in the bores 96.

Also slidable Within the bore 96 is a piston member 104. A bore 106 isprovided in piston 104 having a crosspin mounted therein. The crosspin105 is engaged Within a slot 107 in the pin 101 whereby the piston 104and pin 101 are connected by a lost motion connection comprising slot107 and pin 105. A spring 108 is mounted in engagement with pistonmember 104 and guide 102.

Mounted within the bore 97 is a piston member 110 having a bore 111therein. Mounted within the bore 111 is a crosspin 112. Crosspin 112 isengaged within a slot 13 Vformed in an extension 114 of piston member104. Thus piston member and the piston member 104 are interconnectedthrough a lost motion connection comprising pin 112 and slot 113. Thepiston member 110 has a rod extension 115 connected thereto slidable inbore 9S. The numbers on the drawing in FIGURE 4 for purposes of clarityhave been placed only on the control element 91 although the identicalnumbers would be provided on the control element 90 for the same partssince the control elements 90 and 91 are identical in structure.

Manual adjusting means or levers 116 and 117 are provided to rotate cams92 and 93 respectively. Manual levers 116 and 117 are journalled in anend plate 118 secured to the extension 94 in a known manner as forexample by bolts.

As illustrated in FIGURE 5 a semi-circular portion 119 may be includedon the end plate 122 having indicia thereon indicating the speed ofoperation which has been selected by manual lever 116 or 117 andoperation of cams 92 or 93.

The operation of the control elements 90 and 91 may be described bydescribing the operation of one since they are identical in operationalthough only one is eifective in each cycle of operation. If thevari-able volume pump is rotated in the clockwise direction huidpressure will be supplied to conduit 40 as previously described and thusuid pressure will be admitted through passage 40 into the area betweenpiston members 104 and 110 of the control element 90. Fluid pressurewill thus act on the piston `members to spread them apart due to thelost motion connections putting them in the position illustrated inFIGURE 4 for control element 90 wherein the pin 112 enga-ges the rightend of slot 113. The pin 105 engages the right end of slot 107 due tothe action of spring 108.

Depending on the setting of cam 92 the effective length of controlelement 90 will be established. Fluid pressure imposed on piston members104 and 110 moves the extension 115 of the valve piston member 110 tothe right against the spring 57 a certain extent thereby moving cam ring55 to a predetermined displacement setting of the pump 20. Sincemovement of the cam ring 55 of pump 20 to the right increases thedisplacement of the pump as the cams are vmoved to an increased positionas indicated in FIGURE 5 the speed of operation of the particular fluidmotor being operated in the transmission will increase.

lf the pump for any reason develops a Huid pressure exceeding thatpredetermined in accordance with the design of cam 92, the spring rateof springs 108, and the designed effective differential area betweenpiston members 104 and 110, the piston member 104 may move to the leftagainst the force of spring 108 moving pin 105 toward the left side ofslot 107 and thus allowing the spring 57 to move the cam ring 55 andextension 115 to the left as the pressure increases to decrease pumpdisplacement and thereby controlling the ow of fluid from the pump untilit reaches the predetermined maximum value.

When the pump is operating in the clockwise direction as previouslydescribed fluid conduit 40 is pressurized activating spin motor 24,therefore the control element 90 is designed as a control valve for thespin cycle to establish a certain predetermined uid and ow to besupplied by the pump during the spin cycle dependent upon the speedselected by manual lever 116 and cam 92.

When the pump is operating in the counterclockwise direction aspreviously described, fluid pressure will be supplied to conduit 41 toactivate agitate -motor 22 to oscillate agitator 12. Thus the controlelement 91 is eiective during the agitate cycle to control the speed ofagitation and allow a certain predetermined fluid ow to be developedduring the agitation cycle being dependent upon the setting of `manualmeans 117 and cam 93.

Since generally a greater torque and thereby higher huid pressures arerequired to operate the agitator than to operate the clothes basketduring the spin cycle, the spring 10S of the control element 91 and thedifferential area therein are designed to allow greater maximum ow thanthe spring 108 and differential area of the control element 90.

The improved control mechanism 21 thus includes two control elementswhich are combination pressure regulators and pump displacement controlelements which will allow a predetermined flow and pressure combinationdevelopment and are further adjustable in a novel manner for providingthe proper tlow for the cycle selected. Thus a control element has beenprovided for each of the spin and agitate cycles of a wash machine sothat proper pressure and ow combination can be utilized in each cycle.

Referring to FIGURES 1 and 6 the agitate motor 22 is illustrated. Thea'gitate motor includes a body 120 having a control valve 121 and achamber 122 therein.

Within the chamber 122 is mounted a vane 123 which will reciprocate asuid pressure is admitted to opposite ends of the chamber 122. The -vane123 has an integral hub section 123a and is journalled -for rotationaround and about a vertical .axis extending along the center of Vahollow shaft 124 which is drivingly connected to the clothes basket 11.

The control valve 121 includes a spool 126 having lands 127, 128 and129. The lands 127 and 128 are separated by a groove 130 and the lands128 and 129 are separated by a groove 131. The yarea of the body 10around valve 121 includes ports 135, 136, 137, 138, 139, 140 and 141.Fluid conduits and 146 are connected to ports 136, 140 respectively.Conduits 145 and 146 are exhaust conduits connected to the sump 32.Fluid conduit 41 is connected to the control valve 121 through port 138.

The valve hub section 123a has a circular groove 147 on the top thereofand has a recess 148 in the bottom thereof which is radially extendingfrom the center portion of the vane hub section 123a. On the lower sideof hub section 123:1 is a circular 4groove 147a connected by a passage147b to groove 147. Groove 147 is a'pressure balancing groove designedto equalize the forces on lhub section 123a developed by fluid pressureexisting in groove 147.

Located immediately beneath the fluid chamber 122 are partially arcuatefluid ports 149 and 150. A fluid passage 151 extends vertically from thegrooves =147 to the under side of hub section 123a so as to be at timesin fluid connection with ports 149 or 150. p

A fluid passage 155 connects port 135 of control valve 121 to the port149 of the agitate motor 22. Similarly a conduit 156 connects port 141of the control valve 121 to the port 150 of the agitate motor 22. Afluid passage 157 connects port 137 of control valve 121 to 4the leftside of fluid chamber 122 as viewed in FIGURE 1. Similarly a fluidpassage 158 connects port 139 to control valve 121 to the right side ofuid chamber 122 as viewed in FIGURE l. The iiuid passage 159 connectsport 138 of control valve 121 to the circular groove 147 of vane 123.

A clutch mechanism 23 has been provided to drivingly connect the vane123 to the shaft 1'60 which is in turn drivingly connected to theagitator 12. The clutch 23 includes an extension 164 of body vmember120. The extension 164 is secured to the body Vmember 120 in any knownmanner and includes a bore 165 and a bore 166 therein. The bore 166 isconnected to fluid `passage 41 through a port 167. A bore 165 isconnected to the sump through an exhaust port I168. Shaft 160 has adriver 170 secured thereto having driving lugs 171 and 172 thereon.

A piston 173 is slidably mounted in the bore 166 and is in engagementwith a. dog clutch member 174. The clutch member 174 is slotted asindicated at 176, and 177. The lugs 171 and 172 on driver 170 areengaged in the slots 176 and 177. A spring 1178 is mounted in engagementwith the clutch member 174 and driver 170 urging the clutch member 174and thereby piston 173 downwardly as illustrated in FIGURE l. Clutchmember 174 has teeth 179 thereon drivingly engageable with matingrecesses 180 provided in hub section 123a of vane 123. Recesses 180 willhave driving engagement with the clutch member 174 when fluid pressureis admitted from conduit 41 into bore 166 at which time piston 173 movesup against the force of spring 178 and =will place clutch member 174 inengagement with recesses 180 in vane hub section 12311 thereby providinga driving engagement between the agitator motor vane 123 and the shaft160 connected to drive agitator 12 during the agitation cycle. Theclutch is disengaged during the spin cycle so the agitator can freeWheel and follow movement of the clothes basket.

The operation of the agitator motor is as follows: when the pump 20 isoperated in a direction to deliver fluid pressure to conduit 41 uidpressure will be admitted through port 167 of clutch 23 to actuateclutch 23 as above discussed and drivingly engage vane 123 with theshaft 160 to drive agitator 12. Fluid pressure is also admitted throughport 138, groove i131, port 139, and uid passage 158 to the right handside of uid chamber 122 when valve 121 is in first axial position asillustrated in FIGURE 1. Fluid pressure acting on vane 123 will thusmove vane 123 in the direction of the arrow or clockwise. The Vane 123will continue the clockwise movement until it reaches a terminalposition when the vertical passage 151 passes over the port 149 whichwill allow fluid pressure to ow through port 149, fluid conduit 155 toport 135 of the control valve 1121. Similarly, port 135 is connected tothe sump 32 by way of fluid conduit 156, port150 and rotors 148.

Fluid pressure in port 135 will act on land 127 of the control valve tomove spool 126 to the right as seen in FIGURE l. When the spool 126 ismoved to the right to a second axial position the passage 158 and thefluid chamber :122 on the right side of the agitate motor 22 will beconnected to port 139, groove 131, port 140, and conduit I146 to thesump 32. Thus fluid pressure will be drained from the right side offluid chamber 122 with the spool 126 in the right hand position.

Fluid pressure in port 138 no-w flows through passage 157 to the lefthand side of uid chamber 122 thus acting on vane 123 to move it in thecounterclockwise direction in which direction it will continue untilreaching its terminal position when passage 151 passes over port 150,and recess 148 is over port 149. When the vane 123 has moved in itsclockwise position over port 149 to actuate control valve 121 andreverse the direction of movement of the vane 123, the recess 148 on thelower side of vane 123 will connect the port 150, passage 156, and port141 and the right hand side of control valve 121 to the sump 32 throughclutch mechanism 23 and port 168 thereby draining fluid pressure fromthe right hand side of spool 126 so that spool 126 may move to theright. Thus the vane 123 will continue to oscillate between its extremepositions determined by the length of the arcuate ports 149 and 150` andthe location of the vertical passage 151.

In FIGURE l a modified form of agitate motor 22 is shown wherein avariable stroke of the agitator is available. As ilustrated in FIGURE 10the agitate motor 22 is provided with an additional manual control valve235 and the body portion 122 is provided -with additional arcuate ports136 and 137. Manual valve 235 has a valve spool 240 having lands 241 and242 thereon. The manual valve 235 also includes ports 243, 244 and 245.The port 243 is connected to the fluid conduit y155 by a fluid con` duit250, port 244 of manual valve 235 is connected to the additional arcuateport 136 by conduit 251, and the port 245 of manual valve 235 isconnected to the additional arcuate port 137 by 4iluid conduit 252.

The control valve 121 may also be provided with a ball detent mechanism255 to provide accurate positioning of the control valve 121 in its twoaxial positions.

The agitate motor is illustrated in FIGURE l0 and is operative toprovide a variable stroke of the agitator of the washing machine asreflected iby the stroke of the vane y123 of the agitate motor due tothe use of additional arcuate ports 136 and 137.

The manual valve 235 may be so positioned that fluid pressure in conduit250 cannot ow into either of conduits 251 and 252. In such case port 149is active to provide the reversing feature of the agitate motor and theagitate motor will operate as described above with a terminal positionof vane 123 above port 149.

The manual valve 235 spool 240 may also be moved to a positioninterconnecting fluid conduits 250 and 251. In such case, the agitatorwhen moving clockwise, will move yto a position from that illustrated inFIGURE l to a terminal position in which the uid passage 151 moves overarcuate port 136 at which time uid pressure ywill be conducted to fluidpassage 151, port 136, fluid conduit 251 and lluid conduit 250 toactuate spool 126 of control valve 121 to move the spool to the rightand thereby admit fluid pressure to fluid passage 157 to thus reversethe vane 123 and move it in the counterclockfwise direction. Theterminal position of the vane 123 is thus above arcuate port 136.

The manual valve 235 may also be moved to a position interconnectingiiuid conduit 250 and fluid conduit 252, in such case when the vane 123moves clockwise from the position illustrated in FIGURE 1, the' vanewill move until it is in position over arcuate port 137 at which timethe iluid pressure in fluid passage 151 will be conducted to port 137,conduit 252, valve 235, conduit 250 to actuate control valve 121. Theterminal position of vane 123 is thus above port 137.

The extent of the arcuate port is increased in this modification tolprovide for fluid pressure exhaust through the recess 148 as describedabove when either of the additional arcuate ports 136 or 137 are madefunctional by manual valve 235.

The improved structure in FIGURE 10 provides a means of having avariable .stroke for the agitator of a wash machine or -for the vane ofany uid vane type motor by having two arcuate ports which may beselectively actuated by the use of the manual valve. As used in awashing machine the stroke of the agitator may thus be varied toaccommodate different types of loads Which may be washed within the washmachine.

The spin motor 24 of the hydraulic transmission includes an outer rotorand an inner rotor 186. The outer rotor has recesses 187 therein adaptedto receive the teeth 188 on inner rotor 186. Fluid pressure is admittedduring the spin cycle through condiut 40 as indicated at 189 and in aknown manner will act in the fluid chambers between the teeth 188 of theinner rotor and the recesses 187 of the outer rotor to spin the outerand inner rotors as fluid pressure is received. Conduit 42 is theexhaust ui'd connection for the spin motor which is connected to thespin motor 24 in a known manner as indicated at 190.

The inner rotor 188 is drivingly connected to the hollow shaft 124whichis part of the clothes basket y11 and thus as the inner rotor 186rotates the clothes basket will be rotated at a speed dependent upon theow of fluid admitted from uid conduit 40.

Fluid pressure actuated lock 25 is an improved lock mechanism which isoperative during the agitate cycle to hold the clothes basket 11 fromrotational movement. As the clothes are agitated by agitator 12 in theagitate cycle there will be a tendency for basket 11 to follow movementof agitator 12 and unless it is held from rotational movement, theagitating or washing action would not be obtained.

The fluid pressure actuated lock 25 includes a body portion having 4abore therein. Slidably mounted within bore 196 is a piston 197 having astem or arm 198 thereon with a tapering end portion 199. A port 200 willadmit fluid pressure from conduit 41 into the bore 196. A spring 201 ismounted within the bore 196 and acts on the piston 197 to urge thepiston to the left.

During the agitate cycle when it is desired to hold the clothes basket11 stationary fluid pressure will be supplied from conduit 41 throughport 200 into bore 196 thus moving the piston 196 and stem 198 to theright, as viewed in FIGURE 1, against the force of spring 201.

A series of recesses 202 are provided on the outer periphery of theouter rotor 185. These recesses 202 are of a shape conforming to theshape of end portion 199. Thus as the outer rotor 185 would begin tomove following the movement of agitator 12, fluid pressure acting onpiston 197 will eventually engage the stern 198 Within one of therecesses 202 and thus lock the outer rotor 185 against rotation. Sincethe outer 'rotor 185 is in driving engagement with the inner rotor 186and the inner rotor 186 is drivingly connected to the clothes basket 11.The action of stem 198 holding the outer rotor 185 against rotation will-be effective to hold clothes lbasket 11 `against rotation.

Thus at a convenient location remote from the clothes basket 11 a fluidpressure actuated lock has been provided of simple design which will beeffective to hold the clothes basket in response to actuation of theagitate uid pressure circuit.

The spin brake valve 26 includes a valve body 21() having ports 211,212, 213 and 214 therein. Port 211 communicates with uid conduit 42;port 212 communicates with uid conduit 40; port 213 communicates withiluid conduit 49 and port 214 communicates with fluid conduit 50.Conduits 49 and 50 flow to sump 32. Valve body 210 includes a bore 229having a valve spool slidable therein.

A spring 222 is mounted in the bore 220 in engagement with spool 221 andurges the spool 221 to the left as viewed in FIGURE l. The spool 221 hasa large groove 224 and small grooves 22S and 226 therein. The spool isfurther provided with a hollow section 228 within the spool. Ports 229and 230 are provided in the spool. The port 231) interconnects annulargroove 226 and hollow portion 228 and the port 229 interconnects annulargroove 225 and the hollow portion 228. The port 229 is relatively smalland is effective as a restriction or orice.

The operation of the spin brake valve 26 is as follows: when the uidpump is supplying fluid pressure to fluid conduit 40 and thereby spinmotor 24 during the spin cycle, lluid pressure will also be admittedthrough port 212 of the spin brake valve 26 and will act on the spool221 to move the spool to the right against the force of spring 222 tothe position illustrated in FIGURE 2. In this position the large groove224 is interconnecting ports 211 and 213 of the spin brake valve. Thusexhaust fluid pressure from the spin motor 24 and conduit 42 can owunrestricted to the sump 32 through the spin brake valve and conduit 49.

When the spin cycle is interrupted by the normal cycle timer switch 16when the lid 30 is lifted interrupting the switch 31 therebydeenergizing the motor and stopping the pump 20, iluid pressure will nolonger be admitted to the spin brake valve through port 212 thus thespring will be effective to move the spool 221 of the spin brake valveto the left to the position illustrated in FIGURES 1 and 3. In theposition of the spin brake valve piston in FIG- URE 3 ports 211 and 213of the spin brake valve are again interconnected but fluid now ows fromport 211 through port 230 of the spool 221 into the hollow portion 228and then through restricted passage or port 229 to conduit 49 to thesump. Thus at this time the fluid being exhausted from spin motor 24 isrestricted in its ow to the sump.

A pressure build-up will thereby take place in fluid conduit 42, sincethe clothes basket 11 is still tending to spin it will now drive theinner rotor 186 of the spin motor 24 and spin motor 24 will act as apump pumping fluid into conduit 42. Since the conduit 42 at this timehas a restricted outlet the pressure will build up and serve to stoprelative rotation between the pump elements and thus serve as ahydraulic brake for clothes basket 11.

The improved spin brake valve 26 is therefore an advantageous structurewhich utilizes the spin motor of the transmission as a brake to quicklybring to a stop the clothes basket of a wash machine. Quick stopping ofthe clothes basket is an important consideration in automatic clotheswashers since the clothes basket must be brought to a stop before theagitation cycle can begin and the time taken to stop the clothes basketis directly reflected in the cycle time of the automatic washer.Further, the quick stopping of the clothes basket is a safety feature toprevent injury of a person placing his hand in the basket while it ismoving. The spin brake valve 26 is of simple construction and operatesautomatically in response to the iluid pressure condition in the conduit40.

The operation of the hydraulic transmission of the present invention insummary is as follows: the timer or selector switch 16 of the automaticwasher schematically represented by switch 16 will select either thewash or spin cycle for the hydraulic transmission. The speed of themotor involved in the particular cycle will be controlled by manualadjustment of means 116 or 117 to change the effective length of therespective control valve or 91 and thus the position of cam ring 55 ofpump 20.

If the agitate cycle is selected the pump 20 supplies fluid pressure toconduit 41. The pressure and flow developed by pump 20 and thereby thespeed of agitate motor 22 will depend upon adjustment of control valve91 `for the agitate cycle, as illustrated in FIGURE l, by manual means117 Ias previously described. Fluid pressure in conduit 41 will serve toactuate the lock 25 to hold the clothes basket 11 stationary in themanner described above. It will also actuate the clutch 23 as describedabove to drivingly interconnect the agitator and the agitate motor 22.Fluid pressure admitted to the agitate motor from conduit 41 and port138 will serve to actuate the vane 123 of the agitate motor so that itoscillates from one terminal position to the other to oscillate theagitator 12 of the wash machine in a manner previously described. Atthis time the spin brake valve 26 will be in a position as illustratedin FIGURE 1.

When the timer or selector switch 16 then selects the spin cycle thepump will stop operating in the direction supplying pressure to conduit41 and will begin to rotate in the direction to supply fluid pressure tocond-uit 40. The flow developed by the pump 20 will now be controlled bymanual adjustment of the control valve 90 controlling the position ofthe cam ring 55 of the pump. Thus a speed can be selected for the spinof the clothes basket 11 at this time by adjustment of the pumpdisplacement by manual means 116.

Fluid pressure in conduit 40 will now be delivered at 189 to the spinmotor 24 to actuate the spin motor and the spin motor will thereby drivethe clothes basket 11 to spin dry the clothes. The lock mechanism 25 isat this time released since no iluid pressure exists in conduit 41 andspring 201 will move the piston 197 to the left disengaging the endportion 199 from one of the recesses 202 in the outer elements of thespin motor 24. Fluid pressure in conduit 4t) as described will move thespin bra-ke valve 26 to a position as illustrated in FIGURE 2 allowinglfree ow of exhaust luid pressure to the sump from the spin motor 24.

At this time since no uid pressure exists in conduit 41 the spring 178will serve to disenga-ge the clutch 23 which had previously provided adriving connection between the agitator motor vane 123 and the agitator12.

As will be apparent from the above description the present inventionprovides a hydraulic transmission incorporating an improved variablevolume uid pump in which uid pressure is conveniently utilized tobalance the vanes and insure that they will be in engagement with thecam ring of the pump without necessity of utilizing springs with eachvane.

Further, the present pump utilizes large cavities 63 and 64 `for theinlet and exhaust ports of the pump which will insure adequate fluid owthrough the pump.

Various features of the invention have been particularly shown anddescribed; however, it should be obvious to one skilled in the art thatvarious modifications may be made therein without departing from thescope of the invention.

We claim:

1. A variable volume fluid pump comprising a body, a rotor mountedwithin said body, a cam ring surrounding said rotor, a plurality ofradial slots in said rotor, a vane carried by each of said slots andslidable therein, one end of said vanes engaging said cam ring to definea plurality of uid chambers, a port plate interposed between said bodyand said rotor and cam ring, a pair of uid cavities in said port plate,fluid inlet and outlet passages in said body each n uid communicationwith one of said cavities, first arcuate ports in said port plateproviding uid communication between each of said cavities and aplurality of said fluid chambers, second arcuate and symmetrical portsin said port plate providing uid communication between each of saidcavities and a plurality of said slots whereby uid pressure in saidcavities will be supplied to said slots in the area of each cavity tourge said vanes into enga-gement with said cam ring in either directionof rotation of the pump and third arcuate ports in said port plate whichserve to supply uid pressure from the uid pressure outlet cavity of saidpump to the slots in the area of said rotor between said cavities.

2. A variable volume uid pump as claimed in claim 1 wherein means insaid port pl-ate interconnects the outlet pressure cavity with saidthird arcuate ports.

3. A variable volume fluid pump as claimed in claim 2 wherein said meansincludes a fluid pressure recess in fiuid communication with said thirdarcuate ports and substantially parallel to said cavities.

4. A variable volume uid pump as claimed in claim 3 wherein said uidpressure recess is connected by uid passages means to each of saidcavities and said uid pressure recess include means operative toautomatically interrupt fluid communication between said fluid cavityand said uid pressure recess and allow fluid communication 12 betweenthe uid pressure outlet cavity and said uid pressure recess.

' 5. A variable volume uid pump as claimed in claim 4 wherein said meanscomprises a ball movable to block one of said uid passage meansinterconnecting the cavities and said fluid pressure recess.

6. A variable volume fluid pump as claimed in claim 5 wherein said rotoris operable in either direction of rotation.

References Cited UNITED STATES PATENTS 2,141,171 12/1938 Centervall103-136 2,214,552 9/ 1940 Ferris 103-38 2,641,195 6/ 1953 Ferris 103-1362,738,774 3/ 1956 Rosaen 103-13 6 2,775 ,946 l/ 1957 Hufferd 103--1202,955,542 10/1960 Gaubatz 10S-120 3,242,703 3/ 1966 Brundage 60-53 FREDC. MATTE/RN, JR., Primary Examiner.

WILBUR J. GOODLIN, Assistant Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE 0F CCRRECTION Patent No.3,396,666 August 13, 1968 Yumus E. Moochhala et a1.

It is certified that error appears in the above identified patent andthat said Letters Patent are hereby corrected as shown below:

Column 4, line 64, "only on the control element" should read on thecontrol elements 90 and 91 and are identical in structure lines 65 to67, cancel "91 although the identica] numbers would be provided on thecontrol element 90 for the san parts since the control elements 90 and91 are identical in structure". Column 5, line 40, cancel "maximum".Column 6, line 22, "Groove 147" should read Groove 147a Column 7, line12, "port 135", each occurrence, should read port 141 line 14, "rotors148" should read recess 148 Column 8, line 62, "piston 196" should readpiston 197 line 69, before "stem 198" insert end portion 199 of line 74,after "of" insert the end portion 199 of Signed and sealed this 11th dayof August 1970.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. WILLIAM E. SCHUYLER, JR. Attesting OfficerCommissioner of Patents

